Best Mini Bike Torque Converters: 30 Series and 40 Series Kits
The best mini bike torque converters: iParts 30 series for 212cc engines, a Comet TAV2 replacement, GYMMEDS, FVRITO Super 30 with riser and a 40 series kit.
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For a 196cc or 212cc mini bike with a 3/4 in crankshaft, the iParts 30 series torque converter (8 HP) is the kit we would buy: a 3/4 in bore, a choice of a 10-tooth sprocket for 40/41 chain or a 12-tooth for #35 chain, and a 2-year warranty (per the Amazon listing). Engines with a 5/8 in shaft or no room for the driven pulley need the FVRITO Super 30 kit with its riser plate and shaft sleeve.
A torque converter is a CVT: King Midget Car Club's shop notes on Comet torque converters explain that it runs a numerically high ratio at low RPM for pulling power and the reverse at high RPM for speed. Picks were compared on shaft size, sprocket options, included parts and warranty.
Our top picks at a glance
1. Best overall
iParts Expert 30 series torque converter (8 HP)Series: 30 · Driver bore: 3/4 in · Sprockets: 10T 40/41, 12T 35 · Warranty: 2 years
2. Best Comet TAV2 replacement
iParts Expert 30 series torque converter (6.5 HP)Series: 30 (TAV2 type) · Driver bore: 3/4 in · Sprockets: 10T 40/41, 12T 35 · Warranty: Not stated
3. Best for two shaft sizes
GYMMEDS 30 series torque converterSeries: 30 · Driver bore: 3/4 in and 5/8 in drivers · Sprockets: 10T 40/41/420, 12T 35 · Warranty: 1 year
4. Best complete kit
FVRITO Super 30 series torque converter kitSeries: Super 30 · Driver bore: 3/4 in (sleeve for 5/8 in) · Sprockets: 10T and 12T · Warranty: 90 days
5. Best budget TAV2 fit
MOJTBE 30 series torque converterSeries: 30 · Driver bore: 3/4 in · Sprockets: 10T 40/41/420, 12T 35 · Warranty: Not stated
6. Best for big engines
JZSWYST 40 series torque converter kitSeries: 40 · Driver bore: 1 in · Sprockets: Not stated · Warranty: None
| Pick | Series | Driver bore | Sprockets | Warranty | Buy |
|---|---|---|---|---|---|
| iParts Expert 30 series torque converter (8 HP)Best overall | 30 | 3/4 in | 10T 40/41, 12T 35 | 2 years | Amazon |
| iParts Expert 30 series torque converter (6.5 HP)Best Comet TAV2 replacement | 30 (TAV2 type) | 3/4 in | 10T 40/41, 12T 35 | Not stated | Amazon |
| GYMMEDS 30 series torque converterBest for two shaft sizes | 30 | 3/4 in and 5/8 in drivers | 10T 40/41/420, 12T 35 | 1 year | Amazon |
| FVRITO Super 30 series torque converter kitBest complete kit | Super 30 | 3/4 in (sleeve for 5/8 in) | 10T and 12T | 90 days | Amazon |
| MOJTBE 30 series torque converterBest budget TAV2 fit | 30 | 3/4 in | 10T 40/41/420, 12T 35 | Not stated | Amazon |
| JZSWYST 40 series torque converter kitBest for big engines | 40 | 1 in | Not stated | None | Amazon |
Best overall
iParts Expert 30 series torque converter (8 HP)
For 212cc engines with a 3/4 in shaft.
- Series
- 30
- Driver bore
- 3/4 in
- Sprockets
- 10T 40/41, 12T 35
- Warranty
- 2 years
Pros
- Rated for 8.0 HP 212cc engines
- 2-year warranty
Cons
- Needs a riser on some frames
iParts lists this 30 series kit for 212cc engines with 8.0 HP output, a 3/4 in shaft and 10T 40/41 or 12T #35 sprocket options, with a 2-year warranty (per the Amazon listing).
Best Comet TAV2 replacement
iParts Expert 30 series torque converter (6.5 HP)
For replacing a worn stock 30 series unit.
- Series
- 30 (TAV2 type)
- Driver bore
- 3/4 in
- Sprockets
- 10T 40/41, 12T 35
- Warranty
- Not stated
Pros
- Three drive belts included
- Belt length 27.76 in, 6-15/16 to 7 in center to center
Cons
- Warranty not stated
iParts calls this a direct replacement for the Comet TAV2 30 series, for engines with a 3/4 in straight crankshaft, and lists its belt as 70.5 cm (27.76 in) long and 3/4 in wide, with 6-15/16 to 7 in between driver and driven centers (per the Amazon listing). It lists fit for the Coleman BT200X and CT200U.
Best for two shaft sizes
GYMMEDS 30 series torque converter
For owners unsure of their crankshaft size.
- Series
- 30
- Driver bore
- 3/4 in and 5/8 in drivers
- Sprockets
- 10T 40/41/420, 12T 35
- Warranty
- 1 year
Pros
- Both 3/4 in and 5/8 in driver pulleys
- 1-year warranty
Cons
- Recommended for 2 to 7 HP engines
GYMMEDS lists a 30 series kit with both a 3/4 in and a 5/8 in driver pulley, a 12T sprocket for #35 chain and a 10T for 40/41/420, recommended for 2 to 7 HP engines including the Predator 212, with a 1-year warranty (per the Amazon listing).
Best complete kit
FVRITO Super 30 series torque converter kit
For a first converter swap on a Predator 212 or 196.
- Series
- Super 30
- Driver bore
- 3/4 in (sleeve for 5/8 in)
- Sprockets
- 10T and 12T
- Warranty
- 90 days
Pros
- Engine riser plate included
- Crankshaft sleeve for 5/8 in shafts
Cons
- 90-day warranty
- Stock is scarce
FVRITO lists its Super 30 kit with a 212 engine riser plate, which it calls essential for putting a converter on a Predator 212 or 196, a 3/4 in driver with a sleeve for 5/8 in crankshafts, 10T and 12T sprockets and a 30 series belt, with a 90-day warranty (per the Amazon listing).
Best budget TAV2 fit
MOJTBE 30 series torque converter
For owners who know their Comet part number.
- Series
- 30
- Driver bore
- 3/4 in
- Sprockets
- 10T 40/41/420, 12T 35
- Warranty
- Not stated
Pros
- Lists Comet 218353A, 219552A, 219456A, 217610A
- Fits horizontal-shaft engines
Cons
- No warranty listed
MOJTBE lists a 3/4 in 30 series replacement for Comet TAV2 units 218353A, 219552A, 219456A and 217610A, for 2 to 8 HP horizontal-shaft engines (per the Amazon listing).
Best for big engines
JZSWYST 40 series torque converter kit
For 8 to 16 HP engines like a 420cc.
- Series
- 40
- Driver bore
- 1 in
- Sprockets
- Not stated
- Warranty
- None
Pros
- For 8 to 16 HP engines
- Engagement about 2,350 RPM
Cons
- Will not fit a 3/4 in 212cc shaft
- No warranty
JZSWYST lists a 40 series kit with a 1 in driver and 3/4 in driven pulley for 8 to 16 HP engines such as the Predator 420, with engagement around 2,350 RPM, plus or minus 200, and no warranty (per the Amazon listing).
How a mini bike torque converter works
A torque converter has three parts: a drive clutch on the crankshaft, a driven pulley and a belt, per King Midget Car Club's notes on Comet units. As RPM rises, weights in the driver push the belt higher on the driver pulley, and the driven pulley opens to let the belt ride lower, so the ratio shifts from low (pulling) to high (speed). A plain centrifugal clutch, like the one on the Coleman CT200U, has one fixed ratio.
Choosing a kit
Shaft size
Measure the crankshaft. Most 196cc and 212cc engines, including the maXpeedingrods and GENMAX engines in our 212cc picks, have a 3/4 in shaft with a 3/16 in keyway. A 5/8 in shaft needs a sleeve or a 5/8 in driver; a 1 in shaft needs a 40 series.
Chain size
Kits ship with a 10T sprocket for 40/41/420 chain and a 12T for #35 chain. Match the chain your axle sprocket uses; see mini bike chains.
Mounting and belt alignment
The fixed faces of the driver and driven pulleys should sit opposite each other so the belt stays aligned and does not wear or lose power, per King Midget. If that is not possible, set the belt straight at maximum RPM. A riser plate (FVRITO) lifts the engine so the driven pulley clears the frame.
Belt tension
Comet sizes belts for a set center-to-center distance. King Midget's alternative check: 1 to 1-1/2 in of slack halfway between the pulleys. Too little slack can hinder shifting or cause damage; too much can cost top speed.
What to skip
Skip a 40 series on a 212cc engine and a 30 series on a 420cc. Skip running without the converter cover, and keep hands clear of the belt with the engine running. To see what gearing changes do to speed, use the top speed calculator; for the base bike, see the best mini bikes.
Frequently asked questions
What does a torque converter do on a mini bike?
It works as a CVT: a low, numerically high ratio at low RPM for pulling away and climbing, shifting to a higher ratio as RPM rises for speed, per King Midget Car Club's notes on Comet units.
What size torque converter do I need for a 212cc engine?
A 30 series with a 3/4 in driver bore, the size the iParts, GYMMEDS and MOJTBE kits list. A 40 series with a 1 in bore is for 8 to 16 HP engines like a 420cc.
Does a torque converter make a mini bike faster?
It can raise top speed and low-end pulling at once, because its ratio changes with RPM. Gearing and governed RPM still set the ceiling; try the top speed calculator.
How tight should a torque converter belt be?
Comet sizes belts for a set center distance; King Midget Car Club suggests 1 to 1-1/2 in of slack halfway between the pulleys as a check.
Do I need a riser plate for a torque converter?
Often, on Predator 212 and 196 swaps: FVRITO calls its riser plate essential for fitting a converter to those engines so the driven pulley clears the frame.
What chain goes with a mini bike torque converter?
Kits include a 12T sprocket for #35 chain and a 10T sprocket for 40/41/420 chain. Use the one that matches your axle sprocket.
Sources
- F-6 Comet Belt Alignment and Tension (Shop Notes), King Midget Car Club
- Coleman Powersports CT200U Owner's Manual, Coleman Powersports
Cover image: Illustration: Mini Bike Review (AI-generated)
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